This proposal investigates the beta adrenergic-adenylate cyclase system using healthy, sensitized, and anaphylactic, guinea pig lungs and rat mast cells as models of healthy individuals, asthmatics in remission, and asthmatics undergoing an attack. The parameters being measured are: (a) the number of functional binding sites; (b) the dissociation constants of several receptor agonists; (c) the basal and hormone stimulated adenylate cyclase activities; and (d) the membrane phospholipid and fatty acid composition. These parameters are determined under control conditions and after the lungs have been treated (a) to produce super or subsensitivity of the receptor; (b) with phospholipase A2; or (c) with guanylyl-imidodiphosphate. These parameters will establish whether or not the disruption is inherent in the receptor, related to the receptor-enzyme coupling, in the cyclase per se, or not associated with this system. By comparing the treated samples (nonsensitized) with the nontreated sensitized samples, it will be possible to determine if the states produced by any of the treatments mimic that of the sensitized lung (and assuming the model is a good approximation, the asthmatic in remission).